1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef _LIBCPP___FUNCTIONAL_NOT_FN_H 11 #define _LIBCPP___FUNCTIONAL_NOT_FN_H 12 13 #include <__config> 14 #include <__functional/invoke.h> 15 #include <__functional/perfect_forward.h> 16 #include <utility> 17 18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 19 #pragma GCC system_header 20 #endif 21 22 _LIBCPP_BEGIN_NAMESPACE_STD 23 24 #if _LIBCPP_STD_VER > 14 25 26 struct __not_fn_op { 27 template <class... _Args> 28 _LIBCPP_HIDE_FROM_ABI 29 _LIBCPP_CONSTEXPR_AFTER_CXX17 auto operator()(_Args&&... __args) const 30 noexcept(noexcept(!_VSTD::invoke(_VSTD::forward<_Args>(__args)...))) 31 -> decltype( !_VSTD::invoke(_VSTD::forward<_Args>(__args)...)) 32 { return !_VSTD::invoke(_VSTD::forward<_Args>(__args)...); } 33 }; 34 35 template <class _Fn> 36 struct __not_fn_t : __perfect_forward<__not_fn_op, _Fn> { 37 using __perfect_forward<__not_fn_op, _Fn>::__perfect_forward; 38 }; 39 40 template <class _Fn, class = enable_if_t< 41 is_constructible_v<decay_t<_Fn>, _Fn> && 42 is_move_constructible_v<decay_t<_Fn>> 43 >> 44 _LIBCPP_HIDE_FROM_ABI 45 _LIBCPP_CONSTEXPR_AFTER_CXX17 auto not_fn(_Fn&& __f) { 46 return __not_fn_t<decay_t<_Fn>>(_VSTD::forward<_Fn>(__f)); 47 } 48 49 #endif // _LIBCPP_STD_VER > 14 50 51 _LIBCPP_END_NAMESPACE_STD 52 53 #endif // _LIBCPP___FUNCTIONAL_NOT_FN_H 54